Independent report: Climate science considerations of global mitigation pathways and implications for New Zealand mitigation pathways

In 2020 we commissioned an independent short study on the science of mitigation pathways consistent with limiting warming to 1.5˚C, focusing on trade-offs between pathways that involve reductions in different gases.

The work was undertaken by climate scientists from outside Aotearoa and reviewed by experts familiar with emissions in Aotearoa. The paper was written by Piers Forster (University of Leeds), Richard Millar (UK Climate Change Committee) and Jan Fuglestvedt (Centre for International Climate and Environmental Research Norway).

The paper highlights several findings:

• It is still possible for the world to limit warming to below 1.5˚C – future warming will be determined by the number of greenhouse gas emissions over the coming decades
• In modelled scenarios, keeping warming to 1.5˚C requires long-lived emissions to reach net zero and a reduction in short-lived gases such as biogenic methane by 2050
• There are multiple possible global pathways compatible with 1.5˚C
• Pathways that reach net zero long-lived emissions sooner allow a greater rate of short-lived emissions to be maintained and vice-versa
• What the contribution from Aotearoa New Zealand should be to the global effort is not a scientific question but one driven by fairness and equity principles